Lawler, thank you for taking the time to write such a well considered response!
1) Thanks! I think that having an octave guitar and two baritones really helps. In fact we're planning to acquire more of these special guitars in the future.
3) I used a Olympus LS-11 portable recorder, which turned out to work very well here. You can see it in the video. The room is one of the smaller concert halls at the conservatory, with a high ceiling, and that contributes greatly to the sound, of course.
We shot this video at our last rehearsal last spring, and so I unfortunately didn't get any immediate feedback from my students. When we saw each other again this fall, we talked about it, but you know young people, they have already moved on
But the great thing is, we're planning to make more videos this year!